Vowel merger and distinction

As a native of New Jersey, I pronounce words like cot and caught (don and dawn, sock and talk...) with different vowel sounds - most of the time! Many other speakers of English produce this difference too, though the exact quality of their vowel sounds may differ from mine. And many other speakers produce no difference between these sounds, so that pairs like cot and caught sound alike.

This state of affairs raises lots of questions, both empirical and theoretical: How do speakers vary the way they realize this sort of vowel difference in different contexts? What happens when speakers who treat these words differently meet up and start talking to one another? Can people change how they produce vowel differences over their lifespan? What does all of this tell us about how vowels are represented, and how those representations may change?

In previous work I've examined how people change their cot/caught vowels over time as a result of contact with a new regional dialect. I'm currently working with Daniel Ezra Johnson on a project that looks at how such vowel changes vary depending on speech style. Lauren Hall-Lew and I have also assessed various methods of analyzing vowel differences, to help linguists who are interested in this topic choose appropriate methods for their data.

Phonetics of short-a

Speakers in the Mid-Atlantic region may vary the way they produce the short a vowel in words like pan, pass, pad, and pat. Nearly everyone in this region produces a vowel sound in pan which is audibly different from that of pat, but the a in words like pass and pad is more variable - it may sound more like the vowel in pan, more like the vowel in pat, or somewhere in between. Moreover, there are multiple articulatory strategies for realizing these differences.

Paul De Decker and I have studied variation in the acoustic and articulatory characteristics of short-a in New Jersey, using ultrasound to track tongue gestures. Our work indicates that speakers from the same region and community may, from an acoustic standpoint, exhibit qualitatively different tensing systems, consistent with previous work. In addition, even those with the same acoustic system may vary in terms of how this system is articulated. This research raises questions for future study, such as: to what extent do speakers have a "choice" with respect to which articulatory strategy they employ, and how may these strategies be socially distributed?